According to the National Oceanic and Atmospheric Administration (NOAA), much of the watershed avoided surge-related flooding during the height of the storm, as northerly winds kept a large push of water from moving into the Bay. While some locations did experience post-storm surges of two to four feet, even the highest surge was about half of that seen during Hurricane Isabel in 2003.

And while rainfall has raised river flow in the watershed, the U.S. Geological Survey (USGS) has reported that flow conditions remain below record levels—and lower than expected.

Preliminary data from the USGS also show that the accompanying nutrient and sediment loads pushed into rivers from polluted runoff are not expected to approach those seen in 2011 from Hurricane Irene and Tropical Storm Lee. Nor is the flow in the Susquehanna River expected to produce a significant scour of sediment from the Conowingo Reservoir. While nutrients and sediment can disturb the habitat of underwater grasses and marine life, Sandy’s end-of-autumn timing—while underwater grasses are dormant—means that its impact will likely not be as great as that of a super-sized summertime storm.

According to NOAA, much of Sandy’s rainfall is still working its way down the watershed’s rivers. Scientists from NOAA, USGS and other Chesapeake Bay Program partners will continue to conduct in-depth research on Sandy’s effects on the Bay and its resources.